In their simplest form, disposable sanitary napkins comprise an absorbent element (sometimes referred to as an absorbent core) interposed between a pervious body-contacting element (sometimes referred to as a topsheet or an overwrap) and an impervious protective barrier (sometimes referred to as a backsheet). The absorbent element is, of course, intended to receive and contain menses and other vaginal discharges. The body-contacting element is intended to provide more or less comfortable and dry-feeling contact with body surfaces while allowing free passage of fluids therethrough into the absorbent element. The protective barrier is intended to prevent menses or other vaginal discharges which are expelled or which escape from the absorbent element from soiling the user's garments.
In addition to the three functional elements mentioned above, disposable sanitary napkins are generally provided with means for supporting the device adjacent the user's crotch area, even as the user moves, where it can most effectively perform its intended function. Typically, sanitary napkins are provided with an adhesive attachment means for securing the device to the inner crotch area of the user's undergarments.
While previously known sanitary napkins do perform their intended function, each conventional design suffers from certain deficiencies in one or more of absorbency of body fluids, protection of the user's garments from soiling, and/or physical comfort to the user.
With respect to disposable sanitary napkins, at least two general classes presently exist. One such class is identified as being intended for the absorption of medium to high menstrual flows. These sanitary napkins offer a relatively high absorptive capacity. Absorptive capacity is commonly achieved by providing the sanitary napkin with a relatively thick and bulky absorbent member. While having a relatively high absorptive capacity, the bulkiness of the absorbent member may cause a certain degree of wearing discomfort.
A second class of sanitary napkins are intended for light or low menstrual flows and are commonly referred to as pantiliners or pantishields. Sanitary napkins of this class, as a group, are thinner, somewhat more flexible and generally more comfortable than those of the first class. However, sanitary napkins of the second class typically lack the absorptive capacity of sanitary napkins of the first class.
One attempt to provide the benefits of the previously described two classes of sanitary napkins into a single compound sanitary napkin is disclosed in commonly assigned U.S. Pat. No. 4,425,130 issued to DesMarais on Jan. 10, 1984. The compound sanitary napkin of DesMarais comprises a primary menstrual pad and a panty protector joined to one another at their corresponding ends in such a manner that the two constituents are free to move relative to one another along essentially their entire common length. The primary menstrual pad is intended to absorb the bulk of the bodily fluids discharged by the user, while the panty protector is intended to protect the user's garments from soiling. In use, the relative freedom of movement between the primary menstrual pad and the panty protector serves to maintain the primary menstrual pad adjacent the user's crotch region while the panty protector remains associated with the user's undergarment. While the relative freedom of movement between the primary menstrual pad and the panty protector serves to maintain the primary menstrual pad near the user's crotch region, this freedom of movement may lead to a lack of stability if the primary menstrual pad moves laterally beyond the side edges of the panty protector, providing an opportunity for soiling the user's undergarment.
Furthermore, the relative freedom of movement between the primary menstrual pad and the panty protector alone may be insufficient to capture bodily fluid as it exits the wearer's vaginal opening. The primary menstrual pad is preferably narrow enough to at least reside partially within the external genitalia. Optionally, the primary menstrual pad may be wider than the distance between the labia majora, but exhibits a lateral compression or conformability at relatively low forces, such as the forces exerted by the soft tissue of the female external genitalia, such that a portion of the primary menstrual pad is able to at least reside partially within the external female genitalia. By being conformable at relatively low forces, the primary absorbent member remains comfortable during use. In addition, the primary menstrual pad preferably exhibits a resilient recovery to enable the pad to conform to the body as the pad and body interface is subjected to shape changes.
As the primary menstrual pad is made narrower to fit the body, the panty protector preferably remains sufficiently wide enough to provide a stable attachment to the wearer's undergarment and to sufficiently cover the undergarment to protect it from soiling.